CN113023674A

CN113023674A - Natural gas reformer and SOFC power generation system

Info

Publication number: CN113023674A
Application number: CN201911348912.7A
Authority: CN
Inventors: 卫冬生; 刘建中; 赵宇; 马强强; 伍浩坪
Original assignee: Shanghai Qiyao Heavy Industry Co ltd
Current assignee: Shanghai Qiyao Heavy Industry Co ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-06-25

Abstract

The invention discloses a natural gas reforming device and an SOFC power generation system. The natural gas reforming device comprises a combustor, a reforming heat exchanger and a heat recovery combustor. The reforming heat exchanger comprises a combustion cavity, a reforming air inlet pipe and a reforming air outlet pipe, wherein the reforming cavity surrounds the combustion cavity. After the raw gas is chemically reacted in the reforming cavity, the hydrogen-rich gas is supplied to the outside through the reforming exhaust pipe. According to the natural gas reforming device, in order to prevent the reforming heat exchanger from being overheated and prolong the effective working section, the device is designed in a layered mode, namely the bottom burner and the middle heat-supplementing burner, the burner utilizes natural gas to combust to provide heat to slowly heat the whole device in the starting stage of the device, when the reforming reaction condition is reached, the self-heat-supplementing burner supplements natural gas according to the temperature distribution conditions of the reforming cavity and the combustion cavity, so that the temperature of the whole reaction cavity is uniform, and the device has the advantages of compact structure, simplicity in starting, safety in operation and the like, and is suitable for small-sized natural gas reforming hydrogen production supply.

Description

Natural gas reformer and SOFC power generation system

Technical Field

The invention relates to the technical field of fuel cells, in particular to a natural gas reforming device and an SOFC power generation system.

Background

SOFC (Solid Oxide Fuel Cell) uses electrochemical reaction to generate electricity, and has various advantages: the power generation efficiency is high, and is about 50% -60% in the current technical level; the device has no moving parts, and does not generate vibration and noise; the working temperature is approximately between 700 and 800 ℃, the chemical property of nitrogen is stable in the temperature range, no nitrogen oxide is generated, and the method is environment-friendly; the requirement on the quality of a gas source is not high, the hydrogen-rich gas is only needed, and the fuel has wide application. Therefore, due to the energy saving and environmental protection properties of SOFC, it is regarded as one of the important ways of new energy utilization in the future.

The hydrogen-rich gas used by the SOFC needs to be generated by reforming hydrogen production equipment, the reaction for preparing the hydrogen is an endothermic reaction, and a heating device is needed to provide heat required by the reaction. The existing reforming hydrogen production equipment mainly provides a heat source in an electric heating mode, a small part of reforming hydrogen production equipment heated by fossil fuel needs to continuously introduce fuel from the outside, and combustible components and heat in the waste gas of the galvanic pile are not recycled by the two equipment, so that heat cannot be provided for reforming reaction by utilizing exothermic reaction in the galvanic pile to form circulation.

Reforming hydrogen production equipment heated by fossil fuel mostly adopts a direct combustion or catalytic combustion mode to release heat. Reforming hydrogen production equipment adopting catalytic combustion has the defects of complex structure, difficult maintenance, high cost, slow temperature rise and long start-up time; the burner of the reforming hydrogen production equipment adopting direct combustion has the defects of large structure, difficult ignition, unstable combustion, incomplete combustion and the like.

In addition, the existing reforming hydrogen production equipment needs to install a purification device to purify hydrogen and remove moisture, which increases the cost on the other hand.

Accordingly, there is a need to provide a natural gas reformer for a SOFC power generation system and a SOFC power generation system that at least partially address the problems of the prior art.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

To at least partially solve the above problems, a first aspect of the present invention provides a natural gas reforming apparatus comprising:

the reforming heat exchanger comprises a combustion cavity and a reforming cavity, the reforming cavity surrounds the combustion cavity, a catalyst is filled in the reforming cavity, and a reforming reaction is carried out in the reforming cavity to generate a hydrogen-rich gas;

the combustor is positioned below the reforming heat exchanger and communicated with the combustion cavity, and comprises a gas inlet pipe, an air inlet pipe and an ignition device, wherein the ignition device is used for igniting fuel and air in the combustion cavity so as to heat the reforming cavity; and

the heat recovery combustor extends into the combustion chamber and is located the top of combustor, the heat recovery combustor with the combustion chamber intercommunication for to the combustion chamber input heat recovery fuel.

According to the natural gas reforming device for the SOFC power generation system, in order to prevent the reforming heat exchanger from being overheated and prolong the effective working section, the natural gas reforming device is designed in a layered mode, namely the bottom burner and the middle heat-supplement burner, the burner utilizes the natural gas to burn and provide heat to slowly heat the whole device in the starting stage of the device, and after the reforming reaction condition is achieved, the heat-supplement burner is started according to the temperature distribution conditions of the reforming cavity and the combustion cavity, so that the temperature of the whole reaction cavity is uniform.

Furthermore, the part of the heat-supplementing burner in the combustion cavity is provided with heat-supplementing burners at preset intervals.

Furthermore, the reforming heat exchanger further comprises a smoke exhaust cavity, the smoke exhaust cavity surrounds the reforming cavity, the upper portion of the smoke exhaust cavity is communicated with the combustion cavity, and a smoke exhaust pipe is arranged on the lower portion of the smoke exhaust cavity.

Further, the natural gas reforming device also comprises a catalyst loading and unloading device which is communicated to the reforming cavity from the upper part of the reforming heat exchanger and is used for loading and unloading the catalyst.

Further, the natural gas reforming apparatus further includes a temperature detection device, and the temperature detection device includes:

the combustion chamber temperature measuring connecting pipe extends from the upper part of the reforming heat exchanger to the combustion chamber and is used for detecting the temperature of the combustion chamber;

and the reforming cavity temperature measuring connecting pipe extends from the upper part of the reforming heat exchanger to the reforming cavity and is used for detecting the temperature of the reforming cavity.

Furthermore, the natural gas reforming device also comprises an explosion unloading device which is communicated to the smoke exhaust cavity from the upper part of the natural gas reforming device and is used for releasing pressure when the pressure of the smoke exhaust cavity is overlarge.

A second aspect of the invention provides a SOFC power generation system, comprising:

the fuel cell comprises a galvanic pile, a fuel cell and a fuel cell, wherein an anode gas inlet is arranged in the galvanic pile; and

the natural gas reforming apparatus according to the first aspect includes a reforming exhaust pipe, and the reforming exhaust pipe is communicated with the anode gas inlet and is configured to provide the hydrogen-rich gas to the stack.

According to the SOFC power generation system, the natural gas reforming device is used for providing hydrogen-rich gas, the natural gas reforming device is designed in a layered mode for preventing the reforming heat exchanger from being overheated and prolonging the effective working section, namely the bottom burner and the middle heat-supplement burner, the burner utilizes the natural gas to burn and provide heat to slowly heat the whole device in the starting stage of the device, and after the reforming reaction condition is achieved, the heat-supplement burner is started according to the temperature distribution conditions of the reforming cavity and the combustion cavity, so that the temperature of the whole reaction cavity is uniform.

Furthermore, a cathode exhaust port is arranged in the galvanic pile, and the air inlet pipe of the combustor is communicated with the cathode exhaust port and used for inputting cathode gas from the galvanic pile into the combustion cavity.

Further, the galvanic pile is also provided with an anode exhaust port, and the heat recovery burner is communicated with the anode exhaust port and is used for inputting anode gas from the galvanic pile into the combustion cavity.

Further, a temperature sensor is arranged in the galvanic pile, a gas regulating valve is arranged on the gas inlet pipe, the SOFC power generation system further includes a control device electrically connected to the galvanic pile and configured to be able to control an opening degree of the gas regulating valve according to a temperature of the galvanic pile, and the control device is further configured to:

controlling the gas regulating valve to be opened in the starting stage of the SOFC power generation system, igniting by the ignition device, heating the reforming heat exchanger,

when the temperature of the galvanic pile is lower than the preset temperature, the control device controls the gas regulating valve to reduce the opening along with the rise of the temperature,

and when the temperature of the galvanic pile is greater than or equal to the preset temperature, the control device controls the gas regulating valve to be closed.

Drawings

The following drawings of the invention are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In the drawings:

fig. 1 is a schematic perspective view of a natural gas reformer according to the present invention;

FIG. 2 is a schematic cross-sectional view of the natural gas reformer of FIG. 1;

FIG. 3 is a schematic perspective view of a reforming heat exchanger of a natural gas reformer according to the present disclosure;

FIG. 4 is a schematic cross-sectional view of the reforming heat exchanger of FIG. 3;

fig. 5 is a schematic perspective view of a burner of a natural gas reformer according to the present invention;

FIG. 6 is a schematic cross-sectional view of the burner of FIG. 5;

fig. 7 is a schematic flow diagram of the operation of a burner of a natural gas reformer according to the present invention.

Description of reference numerals:

100: natural gas reformer 200: reforming heat exchanger

210: the combustion cylinder 211: combustion cavity temperature measuring connecting pipe

220: the reforming cylinder 221: reforming exhaust pipe

222: reformed intake pipe 223: catalyst loading and unloading pipe

224: reforming chamber temperature measurement connection tube 225: reforming cavity upper sealing plate

226: reforming cavity lower closing plate 227: air inlet flow equalizing plate

228: exhaust flow equalizer 230: smoke exhausting tube

231: smoke exhaust cavity upper sealing plate 232: smoke exhaust pipe

233: pressure relief pipe 234: lower sealing plate of smoke exhaust cavity

235: flue gas flow equalizer 240: heat recovery burner

241: and (3) concurrent heating burner 250: combustion chamber

260: the reforming chamber 270: smoke exhaust cavity

300: the burner 310: gas inlet pipe

320: air intake pipe 330: premixing device

331: the combustion nozzle 332: ignition device

333: flame detection device 340: positioning cylinder

341: the air chamber partition 342: premixing fan cover

343: insulating cavity 344: air distribution cavity

350: temperature adjusting cylinder 351: air distribution plate

352: a positioning block 353: flame protection cover

360: fire observation hole 311: gas nozzle

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

In the following description, a detailed description will be given in order to thoroughly understand the present invention. It is apparent that the implementation of the embodiments of the invention is not limited to the specific details familiar to those skilled in the art. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art.

Fig. 1 and 2 show a natural gas reforming apparatus according to a preferred embodiment of the present invention, including a reforming heat exchanger 200, a combustor 300, and a supplementary heating combustor 240. The reforming heat exchanger comprises a combustion chamber 250 and a reforming chamber 260, wherein the reforming chamber 260 surrounds the combustion chamber 250, a catalyst is filled in the reforming chamber 260, and a reforming reaction occurs in the reforming chamber 260 to generate a hydrogen-rich gas.

The burner 300 is located below the reforming heat exchanger 200 and communicates with the combustion chamber 250, and the burner 300 includes a gas inlet pipe 310, an air inlet pipe 320, and an ignition device 332, wherein the ignition device 332 is used for igniting fuel and air in the combustion chamber 250 to heat the reforming chamber 260.

The supplementary heating burner 240 extends into the combustion chamber 250 and is located above the burner 300, the supplementary heating burner 240 communicating with the combustion chamber 250 for inputting supplementary heating fuel to the combustion chamber 250.

When the natural gas reformer is used as a component of an SOFC power generation system, the natural gas reformer provides a hydrogen rich gas to the SOFC power generation system. SOFC power generation systems include a stack having an anode gas inlet, an anode gas outlet, and a cathode gas outlet. The reforming exhaust pipe 221 of the natural gas reforming device 100 is communicated with the anode gas inlet, and is used for conveying the hydrogen-rich gas generated in the reforming cavity 260 to the stack for electrochemical reaction, one end of the heat recovery burner 240 is communicated with the anode gas outlet of the stack, and the other end is communicated with the combustion cavity 250, and is used for conveying the anode gas generated by the anode of the stack back to the combustion cavity for afterburning.

The burner 300 includes a gas inlet pipe 310, an air inlet pipe 320 and an ignition device 332, one end of the air inlet pipe 320 is connected to the combustion chamber 250, the other end is connected to the cathode exhaust port of the stack, fuel enters the combustion chamber 250 through the gas inlet pipe 310, and air from the cathode of the stack enters the combustion chamber 250 through the air inlet pipe 320.

The fuel and the air are ignited by the ignition device 332 in the combustion chamber 250 to heat the reforming chamber 260, the raw material gas is catalyzed by the catalyst to generate hydrogen-rich gas, the hydrogen-rich gas enters the anode gas inlet of the stack from the reforming exhaust pipe 221 to react, the anode gas generated by the stack enters the combustion chamber 250 through the heat-up burner 240 to perform combustion heat-up, and the cathode gas generated by the stack and the air enter the combustion chamber 250 through the air inlet pipe 320 to supply oxygen for combustion.

When the natural gas reforming device is used for an SOFC power generation system, the natural gas is combusted to provide heat for reforming reaction in the starting stage, the ignition is simple, and the temperature rise speed is high; after reaction occurs in the electric pile, the sensible heat of cathode gas generated by the electric pile, the sensible heat carried by anode gas and chemical heat are gradually switched to provide energy for reforming reaction, and the electric pile has the advantages of energy conservation and environmental protection.

The natural gas reforming device for SOFC power generation system of the present invention will be described in detail with reference to fig. 1 to 7.

Referring to fig. 1 and 2, the natural gas reforming device 100 includes a reforming heat exchanger 200 and a combustor 300. The reforming heat exchanger 200 is used to perform a reforming reaction, and the combustor 300 is located below the reforming heat exchanger 200 and is used to provide heat for the reforming reaction during a start-up stage of the SOFC power generation system. The natural gas reformer 100 thus converts the raw material gas into a hydrogen-rich gas, and supplies the hydrogen-rich gas to the cell stack of the SOFC power generation system for an electrochemical reaction, thereby converting chemical energy into electric energy. The feed gas is preferably natural gas, more preferably a mixed gas of natural gas and steam. The hydrogen-rich gas is preferably a hydrogen-rich gas. The fuel used by the burner 300 is preferably natural gas. The natural gas reformer 100 has a length of about 1m, a diameter of about 20cm, and a weight within 20kg, and primarily provides hydrogen-rich gas to the stack at a power level of about 1 kw.

Referring to fig. 3 and 4, the main structure of the reforming heat exchanger 200 is composed of a combustion cylinder 210, a reforming cylinder 220 and a smoke exhaust cylinder 230. Among them, the combustion cylinder 210 is configured in a cylindrical shape with both ends open, the reforming cylinder 220 is configured in a cylindrical shape with both ends reduced, and the exhaust cylinder 230 is configured in a cylindrical shape with one end closed and the other end reduced. The reforming cylinder 220 is sleeved outside the combustion cylinder 210, and the smoke exhaust cylinder 230 is sleeved outside the reforming cylinder 220, which are approximately concentric. And the length of the reforming cylinder 220 is less than that of the combustion cylinder 210, and the length of the exhaust cylinder 230 is less than or equal to that of the reforming cylinder 220. In an embodiment not shown, the reformer 220, the smoke exhaust 230, and the combustor 210 may be equal in length, and they may be molded by casting.

The reforming chamber upper closing plate 225 of the reforming cylinder 220 is aligned with and connected to the top end of the combustion cylinder 210, the reforming chamber lower closing plate 226 of the reforming cylinder 220 is connected to the upper side wall position of the bottom end of the combustion cylinder 210, and the reforming cylinder 220 and the combustion cylinder 210 are preferably fixed by spot welding and then full welding after being butted.

The chimney 230 is substantially in the shape of a water jar, and the opening of the chimney is downward sleeved on the reforming cylinder 220. And the upper sealing plate 231 of the smoke exhaust tube 230 is not in contact with the top of the reforming tube 220, so that the lower sealing plate 234 of the smoke exhaust tube 230 is connected to the upper side wall of the bottom end of the reforming tube 220, and the smoke exhaust tube 230 and the reforming tube 220 are preferably fixed by spot welding and full welding after being butted.

Thus, the space inside the combustion can 210 constitutes a combustion chamber 250, the cavity between the reforming can 220 and the combustion can 210 constitutes a reforming chamber 260, the gap between the exhaust can 230 and the reforming can 220 is configured as an exhaust chamber 270, and the exhaust chamber 270 communicates with the combustion chamber 250 and surrounds the reforming chamber 260.

The reforming chamber 260 is provided at a lower portion thereof with an intake flow equalizing plate 227 and at an upper portion thereof with an exhaust flow equalizing plate 228. An air inlet buffer chamber is formed between the air inlet flow equalizing plate 227 and the reforming cavity lower sealing plate 226, and the reforming air inlet pipe 222 is communicated with the air inlet buffer chamber; an exhaust buffer chamber is formed between the exhaust flow equalizing plate 228 and the reforming cavity upper sealing plate 225, one end of the reforming exhaust pipe 221 is communicated with the exhaust buffer chamber, and the other end is communicated with an anode air inlet of the electric pile. The catalyst fills the reforming chamber 260 between the inlet flow equalizer 227 and the outlet flow equalizer 228. The catalyst is preferably in the form of pellets, cylinders or spheres to facilitate loading and unloading of the catalyst. In order to increase the specific surface area, the catalyst may have a porous structure.

In other words, the reforming cavity is divided into an air inlet buffer chamber, a reaction chamber and an air exhaust buffer chamber from bottom to top, wherein the reaction chamber is filled with a catalyst; the raw gas enters the gas inlet buffer chamber through the reforming gas inlet pipe 222, then flows through the gas inlet flow equalizing plate 227, then uniformly passes through the reaction chamber, undergoes chemical reaction, then flows through the gas outlet flow equalizing plate 228, and finally is supplied with hydrogen-rich gas through the reforming gas outlet pipe 221.

The lower part of the smoke exhaust cavity 270 is provided with a smoke exhaust and gas homogenizing plate 235, a smoke exhaust buffer chamber is formed between the smoke exhaust and gas homogenizing plate 235 and the lower sealing plate 234 of the smoke exhaust cavity, and the smoke exhaust pipe 232 is communicated with the smoke exhaust buffer chamber.

One end of the heat recovery burner 240 is connected to the anode exhaust port of the stack, and the other end thereof passes through the exhaust cavity upper cover plate 231 from above the reforming heat exchanger 200 and extends into the lower portion of the combustion cavity. And the supplementary heating burners 240 in the combustion chamber 250 are provided with supplementary heating burners 241 at a predetermined distance to uniformly discharge the anode gas in the axial direction of the reforming heat exchanger 200. A supplementary combustion gas adjusting valve is provided on the supplementary combustion burner 240 between the stack and the reforming heat exchanger 200.

Thus, fuel is combusted in the combustion chamber 250, heating the reforming chamber 260, and the resulting flue gas enters the flue gas discharge chamber 270 upward and exits downward through the flue gas discharge pipe 232, and secondarily heats the reforming chamber 260. The raw gas enters the gas inlet buffer chamber through the reforming gas inlet pipe 222, is rectified and equalized, then diffuses upwards and contacts with the catalyst, and reacts under the heating condition to generate hydrogen-rich gas. The hydrogen-rich gas enters the exhaust buffer chamber through the exhaust flow equalizing plate 228, is collected and equalized, and is then delivered to the anode of the stack through the reforming exhaust pipe 221 to participate in the electrochemical reaction. The anode gas generated from the anode of the stack is at a high temperature and a part of the remaining combustible gas is returned to the combustion chamber 250 through the supplementary heating burner 240 to heat the reforming chamber 260 and burn out the remaining combustible gas. The anode gas enters the combustion chamber from the heat recovery burners 241 uniformly distributed on the heat recovery burner 240, so that a temperature field uniformly distributed in the radial direction of the reforming heat exchanger 200 can be formed, which is beneficial to the reforming reaction.

The invention utilizes the heat released by the electrochemical reaction of the galvanic pile and recovers the residual combustible gas, thereby having the advantages of energy saving and consumption reduction and having very high economic and social benefits.

To facilitate the loading and unloading of the catalyst, the reforming heat exchanger 200 further includes a catalyst loading and unloading device, preferably a catalyst loading and unloading pipe 223, disposed above the reforming heat exchanger 200, the catalyst loading and unloading pipe 223 sequentially passing through the smoke discharge cavity upper cover plate 231, the reforming cavity upper cover plate 225, and the exhaust gas flow equalizing plate 228 to be connected to the reforming cavity 260. Since the catalyst is in the form of particles, and the natural gas reforming apparatus 100 has a small volume, it can be directly poured out of the catalyst charge-discharge pipe 223 or charged into the catalyst charge-discharge pipe 223.

In addition, the reforming heat exchanger 200 is also provided with an explosion relief device and a temperature detection device. The explosion relief device is preferably a pressure relief pipe 233, and the temperature detection device comprises a reforming cavity temperature measuring connecting pipe 224 and a combustion cavity temperature measuring connecting pipe 211. The pressure relief pipe 233 is arranged at the upper part of the smoke exhaust tube 230 and communicated with the smoke exhaust cavity 270, and is automatically decompressed when the internal pressure of the combustion cavity 250 and the internal pressure of the smoke exhaust cavity 270 exceed a limit value, so that explosion accidents are prevented, and the pressure relief pipe 233 can be specifically arranged at the top or the side upper part of the smoke exhaust tube 230. The reforming cavity temperature measuring connection pipe 224 passes through the smoke exhaust cavity upper sealing plate 231 and the reforming cavity upper sealing plate 225 in sequence from the upper side of the reforming heat exchanger 200, is connected to the exhaust buffer chamber, and is internally provided with a thermometer for measuring the reaction temperature. The combustion chamber temperature measuring connection pipe 211 penetrates through the smoke exhaust chamber upper sealing plate 231 from above the reforming heat exchanger 200 and is connected to the smoke exhaust chamber 270, and the thermometer is inserted into the combustion chamber 250 from the combustion chamber temperature measuring connection pipe 211 to measure the temperature of the smoke.

Referring now to fig. 5, 6 and 7, the main body of the burner 300 is composed of a positioning cylinder 340 and a temperature-adjusting cylinder 350. The positioning cylinder 340 is configured as a cylinder with a closed bottom end, the temperature adjusting cylinder 350 is configured as a cylinder with two open ends, and the outer diameter of the temperature adjusting cylinder 350 corresponds to the inner diameter of the positioning cylinder 340, so that the temperature adjusting cylinder 350 can be inserted into the positioning cylinder 340 from the upper part of the positioning cylinder 340. The outer diameter of the temperature-adjusting barrel 350 also corresponds to the inner diameter of the combustion barrel 210 of the reforming heat exchanger 200 so that the temperature-adjusting barrel 350 can be inserted into the combustion barrel 210. In the embodiment shown in fig. 1 and 2, the outer diameter of the temperature-adjusting cylinder 350 is equal to the inner diameter of the combustion cylinder 210, the inner diameter of the combustion cylinder 210 is equal to the inner diameter of the positioning cylinder 340, and the burner 300 may be inserted into the reforming heat exchanger 200 from below the reforming heat exchanger 200.

Specifically, referring to fig. 6, a premixer 330, a plenum partition 341, and a premix air cover 342 are disposed in the positioning barrel 340. The air chamber partition plate 341 is positioned at the upper part of the positioning cylinder 340, and the space below the air chamber partition plate 341 forms a heat preservation cavity 343; the premixing air cover 342 is positioned above the air chamber partition 341 and connected to the air chamber partition 341, the premixing air cover 342 and the positioning cylinder 340 are in a substantially concentric structure, a space between the premixing air cover 342 and the side wall of the positioning cylinder 340 forms an air distribution cavity 344, a positioning opening is formed in the upper part of the premixing air cover 342, and the temperature adjusting cylinder 350 is connected to the premixing air cover 342 through a positioning block 352; the premixer 330 is disposed inside the premixing air cover 342 and passes through the air chamber partition 341, and the outer wall of the premixer 330 is provided with a through hole. The premixing fan housing 342 is formed with a plurality of through holes, each through hole has a diameter of about 8mm, and the plurality of through holes are arranged circumferentially, so that the premixer 330 is communicated with the air distribution chamber 344 through the through holes of the premixing fan housing 342 and the through holes.

A gas inlet pipe 310 passes through the positioning cylinder 340 from the bottom of the burner 300 and is connected to the premixer 330 for inputting fuel into the premixer 330; one end of the air inlet pipe 320 is connected to the air distribution chamber 344, and the other end is connected to the cathode exhaust port of the stack. The top of the gas inlet pipe 310 is provided with a gas nozzle 311, fuel from the gas inlet pipe 310 is injected into the premixer 330 through the gas nozzle 311, and air and fuel from the cathode of the stack are mixed into a mixed gas in the premixer 330.

The bottom of the temperature adjusting cylinder 350 is provided with an air distribution plate 351 which is provided with a plurality of air distribution holes, and the diameter of each air distribution hole is about 2 mm. The temperature control cylinder 350 also has a combustion nozzle 331, an ignition device 332, a flame detection device 333, and a flame protection cover 353. The combustion nozzle 331 is disposed above the premixer 330 and communicates with the premixer 330, and the mixture gas mixed in the premixer 330 is ejected from the combustion nozzle 331, and the combustion nozzle 331 is preferably made of a conductive material. The top surface of the combustion nozzle 331 is provided with 8 gas injection holes of 2mm to enable the mixture gas to be uniformly injected.

The ignition device 332 and the flame detection device 333 are disposed at both sides of the combustion nozzle 331, and are spaced apart from each other. The ignition device 332 is used to emit an arc toward the combustion nozzle 331 to ignite the mixture gas. The flame detection device 333 is used to detect the combustion condition of the flame, and when successful ignition is detected, the ignition device 332 stops discharging. The flame protection cap 353 is configured in a cylindrical shape and is fitted over the flame detection device 333, the ignition device 332, and the combustion nozzle 331, for maintaining the stability of the flame during high-wind-volume and/or low-temperature combustion.

In addition, the upper portion of the premixer 330 is configured as a tapered structure that is narrow first and then wide to increase the speed of the mixture gas entering the combustion nozzle 331. The reducing structure may be a venturi structure. The bottom of the positioning cylinder 340 is provided with a fire observation hole 360 for observing the combustion condition of the flame. The fire observation holes 360 extend into the insulating cavity 343, through the insulating material, so that the flame can be observed.

An air flow regulating valve is arranged on the air inlet pipe 320, and a gas regulating valve is arranged on the gas inlet pipe 310, so that the flow can be conveniently regulated. The bottom of the burner 300 also has a snap-in seat for securing the burner 300, and the snap-in seat is preferably a flange.

Operation of the combustor 300 referring to fig. 7, air from the cathode of the stack is split into primary air and secondary air in the air distribution chamber 344. The primary air enters the premixer 330 along a primary air flow path which sequentially passes through the air distribution cavity 344, the through holes of the premixing air cover 342 and the through holes on the premixer 330 to be mixed with the fuel; the secondary air enters the temperature adjusting cylinder 350 along a secondary air flow path which sequentially passes through the air distribution cavity 344 and the air distribution holes, and the flue gas generated by combustion is mixed and subjected to afterburning.

Specifically, the combustor 300 provides heat for the reforming reaction during the startup phase of the natural gas reformer 100. The cathode inlet of the stack is provided with a blower, so that air flows through the cathode and is exhausted from the cathode exhaust port, and then enters the air distribution chamber 344 through the air inlet pipe 320. The primary air enters the premixing air hood 342 through the through holes of the premixing air hood 342, and then enters the premixer 330 through the through holes of the outer wall of the premixer 330 to be mixed with the fuel to form a mixture. The mixture is injected from the combustion nozzle 331 and ignited by the ignition device 332 to heat the combustion chamber 250. The secondary air passes directly upward through the air distribution holes and enters the combustion chamber 250, and the supplementary oxygen makes the fuel completely burn.

As the electrochemical reaction in the stack proceeds, the temperature of the stack gradually increases, the temperature of the cathode gas also gradually increases, and a portion of the unreacted oxygen is contained therein. The hot cathode gas enters the combustion chamber 250 from the burner 300, and the hot anode gas enters the combustion chamber 250 from the supplementary heating burner 240, and the heat carried by the two and the heat generated by the combustion of the two can heat the reforming chamber 260.

Thus, the start-up phase is completed and the maintenance phase is performed, and the reforming reaction is maintained by the heat generated by the reaction of the stack, thereby reducing or even shutting down the fuel input to the combustor 300.

The invention also provides an SOFC power generation system which comprises a galvanic pile, a natural gas reforming device 100 and a control device. The electric pile is a solid oxide fuel cell, and a temperature sensor is arranged in the electric pile.

The afterburning gas regulating valve, the gas regulating valve and the air flow regulating valve can be electric control regulating valves. The control device is electrically connected to the temperature sensor, the ignition device 332, the post-combustion gas regulating valve, the gas regulating valve, and the air flow regulating valve, and is configured to control the opening degrees of the post-combustion gas regulating valve, the gas regulating valve, and the air flow regulating valve in accordance with the temperature of the cell stack.

Specifically, the control device is further configured to control the gas regulating valve and the air flow regulating valve to be opened in a start-up stage of the SOFC power generation system, and control the ignition device 332 to ignite to heat the reforming heat exchanger 200.

When the temperature in the reforming chamber 260 reaches the reforming reaction temperature, the reforming heat exchanger 200 starts to supply hydrogen-rich gas to the anode of the stack, and electrochemical reaction starts to occur in the stack.

As the reaction in the stack progresses, the temperature of the stack gradually increases, and the temperature of the cathode gas and the anode gas gradually increases, so that the cathode gas and the anode gas can return to the combustion chamber 250 to supplement the heating of the reforming chamber 260. At this time, the control device controls the gas regulating valve to reduce the opening along with the rise of the temperature, so as to reduce the consumption of the fuel.

As the electrochemical reaction in the stack further proceeds, the temperatures of the cathode gas and the anode gas may reach or exceed the reforming reaction temperature, at which time the control device controls the gas regulating valve to be closed. After the start-up stage of the SOFC power generation system is finished, the SOFC power generation system enters a maintenance stage, and the heat generated by the reactor reaction and the combustion heat of the cathode gas and the anode gas are used to maintain the reforming reaction in the reforming heat exchanger 200, so that no fuel needs to be input from the outside, the SOFC power generation system can play a role in saving energy and reducing consumption, and has very high economic and social benefits.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Features described herein in one embodiment may be applied to another embodiment, either alone or in combination with other features, unless the feature is otherwise inapplicable or otherwise stated in the other embodiment.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A natural gas reformer, comprising:

2. The natural gas reformer of claim 1, wherein the portion of the reheat combustor within the combustion chamber is provided with reheat burners spaced a predetermined distance apart.

3. The natural gas reforming device of claim 1, wherein the reforming heat exchanger further comprises a smoke exhaust cavity, the smoke exhaust cavity surrounds the reforming cavity, the upper portion of the smoke exhaust cavity is communicated with the combustion cavity, and a smoke exhaust pipe is arranged at the lower portion of the smoke exhaust cavity.

4. The natural gas reformer of claim 1, further comprising a catalyst loading and unloading device communicating from above the reformer heat exchanger to the reforming chamber for loading and unloading the catalyst.

5. The natural gas reforming device according to claim 1, further comprising a temperature detection device, the temperature detection device comprising:

6. The natural gas reforming device as claimed in claim 3, further comprising an explosion relief device communicated from the upper part of the natural gas reforming device to the smoke exhaust cavity for pressure relief when the pressure in the smoke exhaust cavity is too high.

7. An SOFC power generation system, comprising:

the natural gas reformer according to any one of claims 1 to 6, comprising a reforming exhaust pipe in communication with the anode gas inlet for providing the hydrogen-rich gas to the stack.

8. SOFC power generation system according to claim 7, characterised by a cathode exhaust port being provided in the stack, the air inlet duct of the burner communicating with the cathode exhaust port for feeding cathode gas from the stack to the combustion chamber.

9. The SOFC power generation system of claim 8, wherein the stack is further provided with an anode exhaust port, the reheat combustor being in communication with the anode exhaust port for inputting anode gas from the stack to the combustion chamber.

10. The SOFC power generation system according to claim 9, wherein the stack is provided with a temperature sensor therein, wherein the gas inlet pipe is provided with a gas regulating valve thereon, wherein the SOFC power generation system further comprises a control device electrically connected to the stack and configured to control an opening degree of the gas regulating valve according to a temperature of the stack, and wherein the control device is further configured to: